This invention relates to a paintball marker control system. More particularly, but not exclusively, it relates to a control system for regulating the rate of fire of a marker.
The control of paintball markers is of great importance both from a safety viewpoint and also with regard to preventing blockages due to paintballs rupturing within the marker. Safety is a major issue due to the ejection of high velocity projectiles, paintballs, from markers and the possibility of the accidental discharge of paintballs in areas where protective clothing is not mandatory leading to injuries.
Automatic and semi-automatic paintball markers use a compressed gas that is released in order to fire a paintball, to move a bolt that loads the next paintball ready for firing. The bolt is driven back by the gas in order to allow the next paintball to enter the marker's breech. When the marker is fired the bolt moves forward, typically under spring action, partially sealing the breech, and a hammer strikes a gas entry valve to open it. The open valve allows the compressed gas to enter the breech and force the paintball out of the marker. Some of the gas is used to move the bolt back to its loading position and the valve closes.
For a “perfect” paintball it is possible to fire one paintball every 7 ms. A “perfect” paintball is assumed to be perfectly spherical and to fit exactly in the breech and barrel of the marker. Clearly this is not always the case as paintballs can be filled to varying degrees, deformed and have variable diameters. Thus a timing cycle for firing of 14 ms is typically used in order to allow for imperfections in paintballs. This is a compromise between an efficient use of the compressed gas, which decreases with increased firing cycle time, and allowing for variations in the paintballs to provide a substantially uniform firing characteristic for a marker.
The rupturing of paintballs within a marker, either by being “chopped” by the marker's bolt as they fall into the marker's breech, or simply by overpressurizing the breech when firing, can result in internal surfaces of the marker becoming coated with paint. Ruptured paintballs can, eventually, result in the marker not firing properly or indeed jamming.
Current systems for controlling paintball markers typically employ optical sensors to sense the presence of a paintball in the breech of the marker. These systems seek to prevent the accidental rupturing and/or discharge of paintballs by preventing firing of the marker, for example, when a paintball is not wholly within the marker's breech. These systems rely on either sensing reflected light from a paintball in the breech or the interruption of a beam of light as a paintball falls into the breech.
All such optical control systems have a problem, in that, should a paintball rupture in the breech, the optics of the system can become fouled, rendering the system unreliable or possibly even inoperable. Also optical systems must have their sensors screened from stray light sources in order to prevent spurious output signals.
Additionally, reflected light systems have the attendant problem that paintballs typically have multicoloured casings, for example yellow and black, and each colour will have a different reflectivity, thus causing difficulties in measuring the reflected light.
Optical beam interruption systems suffer from the disadvantage that as a paintball enters the breech a lower surface of it will break the beam. This allows the marker's bolt to be thrown forward before the paintball has fully entered the breech and chop the paintball.
One particular control system as disclosed in U.S. Pat. No. 5,727,538 utilizes position sensors to monitor the location of the bolt in conjunction with an electronic sensor to detect the presence of a paintball in order to limit the opportunities for chopping of paintballs. The use of a number of sensors is complicated and can lead to difficulties in implementation. This document also discloses the use of a single optical sensor but states that such a sensor is unreliable because the sensor can readily become clogged with dirt or paint from ruptured paintballs.